Old specimens, fresh answers: Research charts mercury rise in endangered albatrosses

May 13, 2011 By Alvin Powell
“The collections are key,” said Scott Edwards of the Museum of Comparative Zoology's albatross specimens. “These birds were collected without any … thought about mercury.” Edwards' former student Anh-Thu Elaine Vo ’08 has been studying mercury levels in the endangered birds; her findings were published by the Proceedings of the National Academy of Sciences in April. Credit: Rose Lincoln/Harvard Staff Photographer

Research conducted by a Harvard undergraduate has traced the rise of mercury pollution in endangered seabirds and highlighted the importance of museum collections as a time capsule concerning conditions on Earth over the past century.

The research, by Anh-Thu Elaine Vo ’08, now a graduate student at the University of California, Berkeley, details levels in the feathers of endangered black-footed albatrosses from 1880 to 2002, showing increased levels after World War II and after 1990, when Asian industrialization is believed to have increased emissions. Similar studies have documented the rise of environmental mercury levels in other seas, including the Atlantic and the North Sea, but this is the first to do so for the Pacific.

Mercury is known as a highly toxic pollutant that can have detrimental effects on the environment. It can become particularly toxic for top predators in a food web, because the consumption of creatures with lower mercury levels concentrates it in their tissues. This environmental concentration has led to human consumption advisories for some marine predatory fish, such as tuna.

Black-footed albatrosses, with 7-foot wingspans, are among the oceans’ top predators, living on small fish, squid, and crustaceans. Though Vo’s work illustrated that mercury does concentrate in the ’ tissues, it is not known at what level mercury becomes poisonous in the birds. The albatrosses are considered endangered by the IUCN Red List, but the main threat to them is believed to be longline fishing, which snares an estimated 3,000 birds a year.

“We don’t know whether these concentrations are deleterious for this specific species although adverse effects are associated with the observed concentrations in other waterbirds,” said Vo.

Vo’s research was conducted under the guidance of Scott Edwards, an ornithologist and professor of organismic and evolutionary biology, and Michael Bank, a research associate in the Harvard School of Public Health’s Trace Metals Lab, where some of the mercury testing was done, and with the assistance of James Shine, a senior lecturer on aquatic chemistry. It was published online in the Proceedings of the National Academy of Sciences in April.

Vo examined mercury concentrations in feathers taken from two museum collections. One is Harvard’s Museum of Comparative Zoology (MCZ), which had specimens collected from 1880 to 1949, and the second is at the University of Washington, which had more-recent specimens. Vo said the assistance of the Harvard Trace Metals Lab and Dartmouth College Trace Metals Analytical Laboratory were critical to the research because she couldn’t have done the mercury analysis without it.

“We knew from the literature that mercury is highly toxic to animals, and we knew that humans have changed levels of environmental mercury,” Vo said.

The work analyzed levels of total mercury and of methyl mercury, a form of the element that is absorbed into an animal’s body. It also examined isotopes of carbon and nitrogen as a way to rule out the possibility that changes in the birds’ bodies were due to a shift in food sources. The research showed that the level at which the birds fed in the food chain didn’t change appreciably over time.

Bank said there had been speculation that were rising in the Pacific, but the results provided confirmation.

“We don’t have just a model, we have actual data,” Bank said.

Edwards said the research highlights the value of museum collections. The birds in the MCZ’s ornithology collection, of which Edwards is curator, are commonly used by scholars to study their anatomy. But Edwards pointed out that their tissues also function as a time capsule for the world in which they lived.

“The collections are key,” Edwards said. “These birds were collected without any … thought about mercury.”

Bank said the research built on the “ghost” of past collecting work.

“We’ve harnessed the power of past expeditions,” Bank said.

Edwards and Vo said there are several follow-up studies that could be undertaken, including on whether this level of mercury in the tissues is detrimental to the birds’ breeding.

“We don’t really know if this has really impacted their reproductive success,” Edwards said. “I think there are some great follow-up studies to be done.”

Explore further: Five anthropogenic factors that will radically alter northern forests in 50 years

add to favorites email to friend print save as pdf

Related Stories

Research suggests mercury linked to dementia

Nov 16, 2010

New research by Northeastern University professor Richard Deth and academic colleagues in Germany suggests that long-term exposure to mercury may produce Alzheimer’s-like symptoms in people.

Mercury on the rise in endangered Pacific seabirds

Apr 18, 2011

Using 120 years of feathers from natural history museums in the United States, Harvard University researchers have been able to track increases in the neurotoxin methylmercury in the black-footed albatross (Phoebastria ni ...

April fool? No foolin’...

Apr 04, 2011

If you fell victim to an April Fool’s prank, then consider that life can play some of the most ironic jokes of all. On April 1, 2011 the Mercury MESSENGER was taking some of its first images from Mercury’s ...

Study reveals mercury levels in downtown Toronto

Mar 01, 2011

Buildings are not only an intrinsic part of Toronto's landscape, they are also adding mercury to the city's air. As suggested by the findings of a Ryerson University study, it can lead to a negative long-term ...

Study: Mercury can travel long distances

Dec 12, 2005

University of Washington scientists say they may have determined why mercury in the atmosphere might be washed out more easily than earlier believed.

Recommended for you

More, bigger wildfires burning western US, study shows

13 hours ago

Wildfires across the western United States have been getting bigger and more frequent over the last 30 years – a trend that could continue as climate change causes temperatures to rise and drought to become ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Nik_2213
not rated yet May 14, 2011
Sadly, they seem to have lost many of this year's chicks due to the tsunami from the Japanese quake. Even at a metre, that was enough to swamp low-lying nest sites on the Pacific atolls...

More news stories

Six Nepalese dead, six missing in Everest avalanche

At least six Nepalese climbing guides have been killed and six others are missing after an avalanche struck Mount Everest early Friday in one of the deadliest accidents on the world's highest peak, officials ...

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

There's something ancient in the icebox

Glaciers are commonly thought to work like a belt sander. As they move over the land they scrape off everything—vegetation, soil, and even the top layer of bedrock. So scientists were greatly surprised ...

Clean air: Fewer sources for self-cleaning

Up to now, HONO, also known as nitrous acid, was considered one of the most important sources of hydroxyl radicals (OH), which are regarded as the detergent of the atmosphere, allowing the air to clean itself. ...

Scientists tether lionfish to Cayman reefs

Research done by U.S. scientists in the Cayman Islands suggests that native predators can be trained to gobble up invasive lionfish that colonize regional reefs and voraciously prey on juvenile marine creatures.

Leeches help save woman's ear after pit bull mauling

(HealthDay)—A pit bull attack in July 2013 left a 19-year-old woman with her left ear ripped from her head, leaving an open wound. After preserving the ear, the surgical team started with a reconnection ...